Dont want to start this again, but you see the reason A was able to dodge is because he saw sasuke's eyes. If minato tries gai's counter, he would suffer amaterasu regardless of his speed. If he decides to look at his eyes, he would evade amaterasu but tsukuyomi will get him.Ok fair enough xd. Well I don't want to start a huge vs. thread battle like what always happens but I think that Itachi wins if he catches Minato in a genjutsu. If he can't or doesn't do it then Minato will win a ninjutsu and taijutsu battle.
The reason being is that all of Itachi's attacks are too slow to hit Minato.
Amaterasu was dodged by A at point blank range easily and Minato dodged A, so logically he can dodge Amaterasu.
As for the Totsuka sword I know that is too slow to hit Minato with.
What I think would happen though is if Itachi were fully ready for a fight with Minato he would use genjutsu off the bat and then seal him or use Amaterasu to kill him, anything else gives Minato a chance to survive it depending on how quickly he can break the genjutsu and use FTG.